NASA's nuclear Mars tank is go

NASA's plans to land a large nuclear-powered robotic tank on Mars are back on track, with the first section of its "sky crane" hovering lander module delivered from the makers and funding problems ironed out.

US aerospace titan Lockheed Martin announced yesterday that they had shipped the "backshell" for the Mars Science Laboratory (MSL) mission, the top half of the tin in which the rover will fly through space.

As the MSL descends from deep space into the thin atmosphere of Mars, the two-part aeroshell module will steer itself down by ejecting ballast to shift its centre of gravity. The backshell is mounted on a special-for-Mars ablative heat shield base made of cork and silicone, much of which will burn away from atmospheric friction as the spacecraft plunges down.

As the aeroshell nears the surface, it will slow down using a large parachute, then the heat shield base will drop away and the "sky crane" hovering rocket unit will fall out with the rover slung beneath it. The skycrane will descend on retro-rockets, and in the final stages will lower the rover down on a cable to set down on its wheels ready to go. This, apparently, will mean that rover will wind up much closer to the target landing spot - NASA could only predict where the present ones would set down to within a hundred miles or so. The skycrane will then fly away to crash safely somewhere well away from the rover.

Here's a rather groovy vid, courtesy of NASA, for those with Flash and YouTube privileges:

Lockheed's "backshell" - the bit delivered yesterday, the largest the company has ever made - is the top of the round space tin that the whole package arrives in.

Once down, the MSL will follow NASA's Mars strategy and "follow the water" in the hope of finding signs of a habitable environment - or even life - in the Red Planet's past. Nuclear powered, the big-car sized vehicle won't suffer the serious constraints imposed by using solar power on Mars, further from the Sun than Earth. It will be able to tool about drilling into rocks (or "vapourising" them with its laser) for a full Martian year (nearly two Earth ones) before its plutonium battery pack runs out of puff.

The MSL is a way over budget, seemingly, with $1.5bn already spent. There has been talk recently of cancelling it. However, it now seems clear that the programme will proceed. There's more on MSL from NASA here. ®